Grappling apparatus



April 29, 1958 A. G. ANDERSON l 2,832,629

GRAPPLING APPARATUS Original Filedv Sept'. 8. 1954 2 Sheets-Sheet l 22ff/ m 4 2 2541 ,5 5 253 T255 23a- 252 L23/ r232 '5 234 "255 240 241 5-25h -25l 6 57 243V l i 242 z A 24a 244 5*; 2'44 l245' 244 l 5 293 293 22 294 257 I4 4 25e 23- mal/257 63 254Y I 2254 za. 255` \-25a 25 253 252Q S x l d l i s \-2a A 240 if Q 28a V"\ 253 7 2545 23: 252 'J 231 "A I l230'* 29o 28@ L283 29a 28' 282% 285 \..J\ f L/ ffl l//J/J////A)/////////(- (1l 232j 27o 2325 275 WWNVENTOR:

2 15' 4' 3 ALLAN G. ANDERSON.

April 29, 1958 original Filed sept. s. 1954 2 Sheets-Sheet 2 A, vh

A 1yr-:l 244 c24E y 24| 23o I l A13 X h s l. w g U 15l S I ALLAN G.A/vozpsoN, 231 INVENTOR.

BY, www/fu( I( ATTORNEYS United States Patent O 2,832,629 GRAPPLINGAPPARATUS Allan G.y Anderson, Cheraw, S. C.

Original` application September 8, 1954, Serial No. 454,761. Divided andthis application August 17, 1955, Serial N0. 528,983

19 claims. (ci. 294-63) This invention relates to apparatus for loadingand unloading stacked or bulky materials, such as hacks of bricks andthe like and, more especially, to grapple apparatus for lifting stacksof bricks or other materials and depositing the same.

It is an object of this invention to provide a novel form ot grab orgrappling device operated by a lifting cable, which grab or grapplingdevice comprises a pair of tongs or grappling arms which areautomatically operable to tightly engage opposite sides of the bottomlayer of a stack of bricks or similar material upon alternate upwardmovements of the grappling device and which will, upon the interveningupward movements thereof, automatically release the bottom layer of thestack of bricks or similar material.

lt is another object of the invention to provide novel means forpositively controlling the engaging and disengaging position of the pairof tongs or grappling arms.

It is a further object of the invention to provide novel gripping jawsfor the pair of tongs or grappling arms.

This application is a division of my application Serial No. 454,761filed September 8, 1954 and entitled Apparatus for Loading and UnloadingBricks and the Like.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds when taken in connection withthe accompanying drawings, in which- Figure l is an elevation of thegrappling device showing the jaws thereof having just released thecorresponding stack of bricks or similar articles therefrom;

Figure 2 is a view looking at the right-hand side of Figure l;

Figure 3 is an enlarged fragmentary vertical sectional view takensubstantially along line 3 3 in Figure l;

Figure 4 is an enlarged fragmentary vertical sectional view takensubstantially along line 4-4 in Figure 3;

Figure 5 is an enlarged fragmentary plan view, partially in section,taken substantially along line 5-5 in i Figure 2;

Figure 6 is an enlarged fragmentary plan View, partially in section,taken substantially along line' 6-6 in Figure 2, and showing thegripping jaws at one side of the grappling device;

Figure 7 is a view similar to Figure 4, but showing the gripperoperating or tong operating sear shaft in a different position from thatshown in Figure 4;

Figure 8 is a side elevation of a mobile vehicle or conveyance shown inthe form of a truck-trailer combination showing the improved grapplingdevice secured to the lifting cable of the crane.

Referring more specifically to the drawings, a crane assembly indicatedat 10 is mounted for rotation or oscillation about a vertical axis on asecondary or auxiliary carriage 11. The auxiliary carriage 11 is mountedfor lateral movement on a main or primary carriage 12 which is mountedfor longitudinal movement on a trailer or truck bed or platform 13 of atruck 20. A lifting cable or pliable element 14 of the crane assembly1i) connects 2,832,629 Patented Apr. 29, 1958 ice the novel grapplingdevice broadly designated at 15 for elevating and lowering the samewhile carrying a hack or stack of bricks or similar material A.

For purposes of description, it shall be assumed that the grapplingdevice 15 has been lowered in Figures l to 4 from an elevated positionsuch as shown in Figure 8 to where the stack of bricks or other articlesA is resting upon a supporting surface such as the truck bed 13 or isbeing supported upon any other surface such as the ground upon which thetractor-'trailer combination is positioned.

The grappling device 15 comprises a pair of spaced, side-by-sidesubstantially U-shaped inverted frame members 230, 231 to the lowersurfaces of the horizontal portions of which an inverted U-shaped plate232 is suitably secured and which has down turned portions 233, 234secured to the proximal surfaces of the vertical legs of the invertedU-shaped frame members 230, 231. It will be noted in Figure 2 that theplate 232 and its portions 233, 234 extend outwardly substantiallybeyond opposite sides of the respective inverted U-shaped frame members230, 231 to thereby prevent any bricks in the upper portions of the hackor stack from being dislodged during movement of the hack or stack Afrom one place to another. Horizontal shafts 236, 237 are journaled inthe lower portions of the vertical legs of the inverted U-shaped framemembers 230, 231 and opposite ends of the shaft 236 have the upper endsof gripper arms 246 fixed thereon and opposite ends of the shaft 237have the upper ends of gripper arms 241 fixed thereon.

lt will be noted in Figure 2 that the arms 241 are spaced outwardlysubstantially relative to the distal surfaces of the frame members 230,231. The gripper arms 240 are arranged in the same manner as the gripperarms 241 and support opposite ends of a gripping bar or jaw bar 242. Thelower ends of the gripper arms 241 have opposite ends of achannel-shaped gripper bar 243 suitably secured thereto, and it will beobserved in Figure 6 that there is, supported between the flanges of thechannel-shaped gripper bar 243, a plurality of pivoted gripper jaws 244,of which two are shown in Figure 6.

Each of the pivoted gripper jaws or grappling jaws 244 is pivotallymounted, as at 245, between the upper and lower flanges of thechannel-shaped jaw bar 243 and the inner vertical plate portion of eachof the jaws 244 is provided with one or more resilient or rubber pads246 suitably secured thereto. Each pad 246 preferably has convex inneror article engaging surface thereon. In this instance, there are twosuch resilient pads 246 shown on the inner face of each of the pivotedjaws 244 and it will be noted that there is one of the pads 246 providedfor each horizontal row of bricks or other articles A to thereby insurethat each individual row of bricks is tightly clamped against the jawbar 242 when the jaw bar 242 and the pivoted jaws 244 are moved inwardlytoward each other, as will be later described.

Suitably secured to the central portions ofthe jaw bars 242, 243 are thelower end of respective pairs of -substantially L-shaped levers 250,251, the medial portions of the substantially vertical legs of which arefixed to the respective shafts 236, 237 at points between the framemembers 230, 231. lt will be observed in Figures l, 2 and 4 that thelevers 250, 251 are provided with inwardly and upwardly inclined arms252, 253, respectively, whose proximal portions overlap each other asthey extend through corresponding slots 254 formed in opposite sidewalls 255, 256 of the box-like housing which forms a part of a gripperactivating and deactivating unit broadlyv designated at 257. Saidbox-like structure also includes spaced end walls 260, 261 and it willbe observed in Figures 3 and 4 that the lower edges of said walls 255,256, 260, 261 rest upon the plate 232 and the end walls 260, 261 aresuitably secured to the proximal surfaces of the horizontal portions ofthe inverted U-shaped frame members 238, 231. The proximal surfaces ofthe end walls 268, 261 of the said box-like structure have respectivepairs of spaced projections 263, 264 thereon defining respective groovestherebetween and it will be observed in Figures 3 and 4 that the loweredges of these projections 263, 264 are spaced substantially above theplate 232.

Guided for vertical movement between the proximal surfaces of theprojections 263, 264 is a W-shaped scar block broadly designated at 270and which includes spaced upright projecting portions 71 to 274,inclusive, the upright portions 271, 274 being connected at their lowerends to the lower ends of the intermediate upright portions 272, 273 byrespective horizontal portions 275, 276 and the upper ends of theintermediate upright portions 272, 273 being bridged by a horizontalportion 277.

The term .sear is used herein since the various parts so identied areinstrumental in automatically cooking and uncocking the gripper elementsgenerally in the man ner of a pistol or gun.

1t will be noted that the lower end of the cable 14 is suitablyconnected to the portion 277 of the scar block 270. Journaled in theupright portions 271 to 274, inclusive, of the sear block 278 is a scarshaft 280 whose opposite ends terminate substantially flush with thedistal surfaces of the upright portions 271, 274 of the scar block 270and, extending outwardly from the scar shaft 280 beyond the uprightportions 271, 274 are ground attened portions forming sear keys 281, 282which are, at times, adapted to engage the lower surfaces of theprojections 263, 264 on the walls 260, 261 of said boxlike structure. Atother times, the shaft 280 is rotated, by means to be later described,to where the Sear keys 281, 282 are alined with and thus may pass intothe slots or grooves dened between the adjacent pairs of projections263, 264.

Fixed on the shaft 280 between the closely spaced intermediate portions272, 273 of the sear block 270 is a pair of substantially rectangular orsquare sear cams 283, 284. It will be observed in Figures 4 and 7 thatthe corners of the sear cam 283 are disposed in alinement with the atsurfaces of the scar cam 284 and vice versa. It will also be noted thatthe distance across the corners of the Sear cams 283, 284 is onlyslightly less than the distance between the side walls 255, 256.

The proximal surfaces of the side walls 255, 256 are provided withprojections or ribs 285, 286 thereon which extend inward and whose innersurfaces are spaced from the vertical axis ofthe box-like structuredefined by the .walls 255, 256, 268, 261 a distance slightly greaterthan the distance between opposite fiat edges of each of the rectangularor square cams 283, 284. The projections 285, 286 serve as sear shaftrotating elements and are disposed in off-set relationship and in thevertical planes of the respective sear cams 283, 284. It will beobserved in Figures 4 and 7 that the projection 285 extends upwardlyfrom adjacent the lower edge of the side wall 255 and terminates in aninwardly and downwardly inclined cam surface which is spacedsubstantially below the hori zontal plane of the lower surface of theprojection 286. The lower surface of the projection 286 is also beveledto form a cam surface thereon which extends inwardly and upwardly at anangle. The proximal or upper and lower edges of the respective searshaft rotating elements or projections 285, 286 are necessarily spacedvertically apart sufliciently so that the upper right-hand corner of cam28,4,V in each instance, will clear the lower edge of the projection 286as the upper edge of the projection 285 is engaged Yby the then inclinedlower left-hand surface of the corresponding point of the square cam 283in the course of downward movement of the sear block 270 relative to theprojections 285, 286 from, say, the position shown in Figure 4.

It is apparent that in the course of such downward movement, one cornerof the cam 283 engages the beveled or inclined upper end of theprojection 285 to thus impart one-eighth revolution to the cams 283,284, shaft 280 and its key portions 281, 282. On the other hand, theupper surface of projection 285 should also be spaced sufficiently belowthe lower surface ot projection 286 so that, in the course of upwardmovement of the scar block 270, as imparted thereto by the liftingaction of the cable 14, the then left-hand corner of the cam 283 willclear the upper end of the projection 285 as the then right-hand cornerof the cam 284 engages the lower surface of the projection 286 to impartanother one-eighth revolution to the cams 283, 284, the shaft 280 andthe key portions zar, zsz.

It is thus seen that, when the weight of the grappling device 15 issupported by means other than the cable 14, such as by a stack. ofarticles A or by the lower surfaces of the bars 242, 243 engaging thesurface 57, the sear block 270 and parts supported thereby will occupysubstantially the position shown in Figures 3 and 4. However, uponupward movement of the cable 14, as effected by the crane assembly 18,the scar block 270 moves upwardly relative to the walls 255, 256, 260,261, in the course of which the right-hand corner of the cam 284 inFigure 4 engages the lower earn surface on the projection 286 to therebyeffect one-eighth revolution of movement to the cams 283, 284, the shaft280 and the sear keys 281, 282.

It is apparent that this will cause the at surfaces of the scar keys281, 282 to extend in substantially horizontal planes so that, withfurther upward movement of the scar keys 281, 282, their upper surfaceswill engage the lower surfaces of the projections 263, 264, as shown inFigure 7, to thereby raise the grappling device 15 without exertingupward pressure on the proximal portions of the arms 252, 253 of therespective levers 256, 251. Since the arms 252, 253 overlie the stack ofarticles A, it is apparent that they substantially overbalance thevertical portions of the levers 258, 251 and the parts attached theretoso that, as the scar keys 281, 282 engage the lower ends of theprojections 263, 264 and raise the frame members 230, 231, they alsoraise the lever 250, 251 and the jaw bar 242 and the pads 246 on thejaws 244 (Figure 6) remain clear of the stack of articles A in thecourse of upward movement thereof.

Now, upon the next succeeding and alternate downward movement of thecable 14, and upon the weight of the grappling device 15 being supportedeither by a stack of articles such as the articles A or the surface uponwhich the stack of articles is resting, the sear block 270 andassociated parts move downwardly relative to the box-like structureincluding plates or wall members 255, 256, 261 and, in the course ofsuch downward movement, one of the then horizontally extending pointedportions of the cam 283 engages th'e upper end of and is rotated by theprojection 285 (Figures 4 and 7) to again impart one-eighth revolutionto the cams 283, 284, the shaft 280 and the sear keys 281, 282.

Thus, on the next upward movement ofthe sear block 270, as effected bythe cable 14, the right-hand portion of the cam 284 again engages thelower end of the projection 286 to impart another one-eighth revolutionthereto so the cams 283, 284, shaft 280 and sear keys 281, 282 willoccupy a position revolved ninety degrees from that shown in Figure 7.It is thus seen that, with further upward movement of the sear block270, the sear keys 281, 282 then pass upwardly between the correspondingpairs of projections 263, 264.

Referring to Figure 3, it will be observed that the shaft 280 hasanti-friction bearings or follower members 290 thereon disposed betweenthe portions 271, 272 and 273, 274. In this instance, there are twobearings 290 disposed between the portions 271, 272 and there are twobearings disposed between the portions 273, 274. Thus,.as the sear keys281, 282 move upwardly between the respective pairs of projections 263,264, the bearings 290 engage the lower surfaces of the overlappingportions of the corresponding pairs of arms 252, 253 to thereby impartupward movement to the proximal portions thereof which will, in turn,cause the jaw bar 242 to move inwardly in engagement with one end of thelowermost tier or articles A and this will also cause the resilientmembers 246 on the jaws 244 carried by the jaw bar 243 to move inwardlyin engagement with each row of articles in the bottom tier of articlesA.

Thus, the bottom tier of articles A is tightly clamped between the pads246 on the jaws 244 and the jaw bar 242 so that, with further upwardmovement of the cable 14 and the sear block 270, upward movement is thenimparted to all of the parts of the grappling device 15 along with thestack of articles A.

The stack of articles A is then lifted by pressure exerted on the bottomtier of articles through the arms 252, 253. In the absence of an articleor articles between the jaw bars 242, 243, when the sear keys 281, 282move upwardly between projections 263, 264, the upper ends of portions271, 274 of sear block 27) engage'respective stops 293, 294 xed to theside walls 260, 261. The remaining parts of the grappling device 15 thenmove upwardly with the sear block 270.

It is apparent that, when the cable 14 is lowered with a stack ofarticles and becomes slackened, the jaw bars 242, 243 then move apartfrom each other to release the stack of articles therefrom and willremain in this position as the grappling device 15 is subsequentlyraised and until the grappling device 15 is again lowered and upwardmovement is again initially imparted thereto in the manner heretoforedescribed.

ln the drawings and specification there has been set Vforth a preferredembodiment of the invention and, al-

though specific terms are employed, they are used in a generic anddescriptive sense only, and not for purposes of limitation, the scope ofthe invention being defined in the claims.

l claim:

l. A grappling device having one end connected to a pliable element forbeing elevated and lowered by the same comprising a pair of spacedsubstantially parallel inverted U-shaped frame members, a pair of levershaving substantially vertical lower portions and inwardly divergingpartially overlapping upper portions, the lower portions of said leversbeing j-ournaled intermediate their ends between the lower portions ofthe inverted U-shaped members, a jaw bar fixed to the lower portion ofeach of said levers, a sear block mounted for vertical movement betweensubstantially the central portions of the horizontal portions of saidframe members and to which the lowl er end of the pliable element isconnected, a rotatable sear shaft journaled in said sear block andhaving a sear key integral with at least one end thereof'and projectingoutwardly beyond the sear block, an abutment carred by at least one ofsaid frame members and having its lower surface spaced substantiallyabove the sear key when the sear block is in lowered position, meansengageable with said sear shaft for rotating the same predeterminedamounts upon each vertical movement of said sear block relative to theinverted U-shaped frame members, said last-named means being so arrangedas to cause the sear key to engage the lower end of said abutment uponalternate lifting movements of said pliable element and said sear block,the proximal overlapping portions of the diverging arms of said leversoverlying said seal block `at a point on a level above the level of theabutment whereby said sear key will engage the abutment and lift thegrappling device therewith without creating a lifting force on theproximal overlapping portions of said levers, and said means forrotating the seal shaft being so arranged as to cause `the key to missthe abutment upon lifting movements thereof intervening between saidaltern-ate lifting movements thereof so the sear block will engage theoverlapping portions of said levers to cause rthe lowermost ends of thelevers to move inwardly toward veach other so the jaw bars thereon willclamp articles therebetween.

2. A grappling device having one end connected to a pliable element forbeing elevated and lowered by the same for handling stacked articlessuch as brick and the like comprising a frame, a sear block mounted forvertical movement in said frame and to which the lower end of thepliable element is connected, a pair of levers pivotally supported insaid frame at points in opposed spaced substantially parallelrelationship, article grippingmeans on the lower ends of said levers,rsaid levers having inwardly diverging overlapping portions on theirupper ends whose proximal overlapping portions overlie said sear block,a sear shaft journaled in said sear block and extending transverselyrelative to said overlapping portions of said levers, a transverse searkey on at least one end of said sear shaft and projecting outwardlybeyond said sear block, a pair of spaced abutments carried byA saidframe and norm-ally spaced above said sear key, the distance between theabutments being greater than the width of said key and less than thelength of said key, means engageable with said sear shaft for `impartingsubstantially a one-eighth revolution of rotation to said sear shaftupon each upward and each downward movement of said sear block relativeto said frame, and the lower surfaces of said abutments being spacedbelow the level of the proximate overlapping portions of said leverswhereby, upon alternate lifting movements of the pli-able element andsear block, the hat surface of the sear key will engage the lower endsof said abutments to thereby impart upward movement to said frame and,upon intervening lifting movements of the pliable element land saidVsear block, the sear key will pass between said abutments and willthereby transmit the lifting force to the proximal overlapping portionsof the levers to cause the gripping means on the lower ends thereof tomove inwardly and grip the articles therebetween with further liftingmovement of the grappling device.

3. A structure according to claim 2 having means for limiting upwardmovement of the sear block relative to `the frame in the cour-se of eachof said intervening liftmg movements thereof in the absence of articlesbeing disposed between the article gripping means on the lower ends ofsaid levers.

4. A structure according to claim 2 wherein the gripping meansassociated with at least one of said levers comprises -a plurality ofpivoted jaws each having at least one convex surface thereon forengaging the corresponding surfaces of the articles to be liftedthereby.

5. A structure according to claim 4 wherein said convex surfaces areeach made from a resilient member fixed to the inner surface of thecorresponding jaw.

6. A structure according to claim 2 wherein said sear lblock is providedwith projections in its upper portion defining an opening therebetweenwhereby said projections on the sear block move upwardly astride theproximal overlapping portions of said levers upon said interveninglifting movements thereof, and said shaft having bearing means thereondisposed in said opening betweenthe projections on said sear block sosaid bearing means engage the lower surfaces ofthe proximal overlappingVportions of the lever arms upon said intervening lifting movements ofthe pl-iable element and the sear block.

7. A structure according to claim 2 wherein the means for rotating saidsear shaft substantially a one-eighth revolution with each upward andeach downward movement of the sear block relative to the frame comprisesfirst and second substantially square s-ear cams xed onv said shaft andwherein the points of the first cam extend radially of the planes of thefiat surfaces of/the second cam andY vice versa, a first cam projectionfixed to said frame and being engageable by the first sear cam in thecourse of each upward movement thereof relative to the frame forimparting substantially a one-eighth revolution in rotation to theV searcams and the sear shaft, a second cam. projection spaced from the firstcam projection a distance slightly greater than the distance across theflat surfaces of said sear cams and having its upper surface spacedbelow the level of the lower surface of the first cam projection, andsaid second cam projection being engageable by the second sear cam inthe course of each downward movement thereof for also impartingsubstantially Va one-eighth revolution in rotation to the sear cams andthe sear shaft.

i8. A grappling device having one end connected to a pliable element forbeing elevated and lowered by the same comprising a frame, a pair oflevers having downwardly extending lower portions and inwardly extendingupper portions, said levers being journaled intermediate their ends insaid frame, article gripping means on the lower portion of each of saidlevers, a sear block mounted for vertical movement in Ythe centralportion of said frame and to which the lower end of the resilient memberis connected, Va rotatable sear shaft journaled in said sear block andhaving a sear key integral with at least one end thereof vand projectingoutwardly beyond the sear block, an abutment carried by said frame and'having its lower surface spaced substantially above the sear key whenthe sear block is in lowered position, means engageable with said searshaft for rotating the same predetermined amounts upon each verticalmovement of said sear block relative to the frame, said last-named meansbeing so arranged as to cause the sear key `to engage the lower end ofsaid abutment upon alternate lifting movements of the pliable elementand said sear block, theV proximal upper portions of said levers atleast partially overlying said Sear block at a point on a level abovethe level of the abutment whereby said sear key will engage the abutmentand lift the grappling device therewith without creating a lifting,force on the proximal upper por- -tions of said levers, and said meansfor rotating the sear shaft being so arranved as to cause the key tomiss the abutment -upon lifting movements thereof intervening betweensaid alternate lifting movements thereof so .the sear block will engagethe upper portions of saidrlevers to cause the lowermost ends of thelevers to move inwardly toward each other so the jaw bars thereon willclamp articles therebetween.

9. A structure according to claim 8 having means for limiting upwardmovement of the sear block relative to the frame in the course of eachof said intervening lifting movements thereof in the absence of articlesbeing disposed between the article gripping means on the lowerl ends ofsaid levers.

l0. A structure according to claim 8 wherein the gripping meansassociated with at least one of said levers comprises a plurality ofpivoted jaws each having at least one -convex surface thereon for.engaging the corresponding surfaces of the articles to be liftedthereby.

ll. A structure according to claim l0 wherein said convex surfaces areeach made from a resilient member fixed to the inner surface of thecorresponding jaw.

12. A structure according to claim 8 `wherein said sear -block isprovided with projections in its upper portion revolution with eachupward -and each downward movement of the sear block'relative to theframe comprises first and second substantially square sear cams fixed onsaid shaft and wherein the points of the first cam extend radially ofthe planes of the at surfaces of the second cam and vice versa, andmeans are provided carried by said frame for engaging the first sear camin the course of` each upward movement thereof relative to the frame forimparting substantially a one-eighth revolution in rotation to the searcams and the sear shaft, and to engage the second sear cam in the courseof each downward movement thereof for also imparting substantially aone-eighth revolution to the sear cams and the sear shaft.

la. A structure according to claim 8 wherein the means for rotating saidsear shaft substantially a one-eighth revolution with each upward 1andeach downward movement of the sear block relative to the frame comprisesfirst and second substantially square sear cams fixed on said shaft andAwherein the points of the first cam extend radially of the planes oftheflat surfaces of the second cam and vice versa, a first cam projectionfixed to said frame and being engageable by the first sear cam in thecourse of each upward movement thereof relative to the frame forimparting substantially a one-eighth revolution in rotation to the searcams and the sear shaft, a second cam projection spaced from the firstcam projection a distance slightly greater than the distance across theat surfaces of said sear cams and having its upper surface spaced belowthe level of the lower surface of the first cam projection, and saidsecond cam projection being engageable by the second sear cam in thecourse of each downward movement thereof for also impartingsubstantially a one-eighth revolution in rotation to the sear cams andthe sear shaft.

15. In an article handling device having a cable, and means for raisingand lowering said cable, an improved grapplying device for handlingstacked articles such as brick and the like comprising a frame, a searblock mounted for vertical movement in said frame and to which the lowerend of said cable is connected, a pair of levers pivotally supported insaid frame at points in opposed spaced substantially parallelrelationship, article gripping means on the lower ends of said levers,said levers having inwardly extending upper portions whose proximalportions at least partially overlie said sear block, a sear shaftjournaled in said sear block and extending transversely relative to saidupper portions of said levers, a transverse sear key on at least one endof said sear shaft and projecting outwardly beyond said sear block, apair of spaced abutments carried by said fraine and normally spacedabove said sear key, the distance between the abutments being greaterthan the width of said key and less than the length of said key, meansengageable with said sear shaft for imparting substantially oneeighthrevolution of rotation to said sear shaft upon each upward and Veachdownward movement of said sear block relative tovsaid frame, and thelower surfaces of said abutments being spaced below the level of theproximate upper portions of said levers whereby, upon alternate liftingmovements of said cable and sear'block, the fiat surface of the sear'keywill engage the lower ends of said abntments to thereby impart upwardmovement Vto said frame and, upon intervening lifting movements of saidcable and sear block, the sear key will pass between said abutments andwill thereby transmit the lifting force to the proximal upper portionsof the levers to cause the gripping means on the lower ends thereof tomove inwardly and grip the articles therebetween with further liftingmovement of the grappling device.

16. A structure accordingV Vto claim l5 wherein projections are providedin the upper .portion of said sear block and define an openingtherebetween whereby said upper por-tions of said `levers kupon saidintervening lifting movements thereof, and means are provided on saidshaft disposed in said opening between the projections on said scarblock to engage the lower surfaces of the upper portions of the leverarms upon said intervening lifting movements of the cable and the searblock.

17. A grappling device having one end connected to a pliable element forbeing elevated and lowered by the same comprising a pair of spacedsubstantially parallel inverted U-shaped frame members, a pair of levershaving substantially vertical lower portions and inwardly divergingpartially overlapping upper portions, the lower portions of said leversbeing journaled intermediate their ends between the lower portions ofthe inverted U-shaped members, a jaw bar fixed to the lower portion ofeach of said levers, a sear block mounted for vertical movement betweensubstantially the central portions of the horizontal portions of saidframe members and to which the lower end of the pliable element isconnected, a rotatable sear shaft journaled in said scar block andhaving a sear key integral with at least one end thereof and projectingoutwardly beyond the sear block, an abutment carried by at least one ofsaid frame members and having its lower surface spaced substantiallyabove the sear key when the sear block is in lowered position, rotatablemeans mounted on said sear shaft for movement therewith, driving meansengageable with said rotatable means and for rotating the same and saidsear shaft predetermined amounts upon each vertical movement of saidsear block relative to the inverted U-shaped frame members, said drivingmeans being so arranged as to cause the sear key to engage the lower endof said abutment upon alternate lifting movements of said pliableelement and said sear block, the proximal overlapping portions of thediverging arms of said levers overlying said sear block at a point on alevel above the level of the abutment whereby said sear key will engagethe abutment and lift the grappling device therewith without creating alifting force on the proximal overlapping portions of said levers, andsaid driving means for rotating the sear shaft being so arranged as tocause the key to miss the abutment upon lifting movements thereofintervening between said alternate lifting movements thereof so the searblock will engage the overlapping portions of said levers to cause thelowermost ends of the levers to move inwardly toward each other so thejaw bars thereon will clamp articles therebetween.

18. A structure according to claim 17 wherein said rotatable meansmounted on the sear shaft comprises a pair of opposed and axially alinedmembers provided with drive means engaging portions, and said drivingmeans comprises a first member positioned on the frame and beingengageable with one of the opposed members in the course of each upwardmovement thereof relative to the frame for imparting substantially aone-eighth revolution to one of the opposed members and the sear shaft,and a second member spaced below the first member and being engageableby the other opposed member in the course of each downward movementthereof for also imparting substantially a one-eighth revolution to saidother opposed member and the sear shaft.

19. A grappling device having one end connected to a vertically movableelement for being elevated and lowered by the same, said grapplingdevice comprising a frame, lever means pivotally mounted on oppositesides of the frame and having vertically arranged lower portions andpartially overlapping upper portions, a sear block mounted for verticalmovement in a medial portion of said frame below said overlapping upperportions of said lever means and to which the lower end of thevertically movable element is connected, a rotatable scar shaftjournaled in said sear block and having a sear key integral with a leastone end thereof and projecting outwardly beyond the sear block, anabutment carried by said frame and having its lower surfaces spacedsubstantially above the scar key when the sear block is in loweredposition, means engageable with said sear shaft for rotating the samepredetermined amounts upon each vertical movement of said sear blockrelative to said frame to cause the sear key to engage the lower end ofsaid abutment upon alternate lifting movements of said verticallymovable element and said sear block, the overlapping portions of saidlever means overlying said sear block above said abutment whereby saidsear key will engage the abutment and lift the grappling devicetherewith without creating a lifting force on the overlapping portionsof said lever means, and said means engageable with said sear shaft forrotating the same being so arranged as to cause the scar key to miss theabutment upon lifting movements thereof intervening between saidalternate lifting movements thereof to permit the sear block to engagethe overlapping lever portions of said lever means to cause thelowermost ends of the vertically arranged lever means to move inwardlytoward each other to clamp articles therebetween.

References Cited in the le of this patent UNITED STATES PATENTS

